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Question

的嵌套列表如果在给定的嵌套列表中找到给定的'to_find'，那么如何编写一个返回true的递归函数。

例如：

>>> searchNested([1,[4, 5, 6, [2, 10], 9], [1, 4, 5]], 2) 
True 

Answer 1

展平，然后再使用in

def searchNested(lst,needle): 
    def flatten(target): 
     return_list = list() 
     for element in target: 
      if isinstance(element,list): 
       return_list.extend(flatten(element)) 
      else: 
       return_list.append(element) 
     return return_list 

    lst = flatten(lst) 
    if needle in lst: return True 
    else: return False 

Answer 2

def searchNested(xs, y): 
    if y == xs: 
     return True 
    return isinstance(xs, list) and any(searchNested(x, y) for x in xs) 

---

>>> searchNested([1,[4, 5, 6, [2, 10], 9], [1, 4, 5]], 2) 
True 
>>> searchNested([1,[4, 5, 6, [8, 10], 9], [1, 4, 5]], 2) 
False